Alexander H. Slocum

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We discuss the rapid growth of films and lithographically templated microstructures of vertically aligned small-diameter multiwalled carbon nanotubes (VA-MWNTs), by atmospheric-pressure thermal chemical vapor deposition (CVD) of C2H4/H2/Ar on a Fe/Al2O3 catalyst film deposited by electron beam evaporation. The structures grow to 1 mm height in 15 min and(More)
This paper reports the design, fabrication and testing of a thermally -actuated bistable MEMS relay. Mechanical bis tability ensures zero actuation power in both the on and off states, and permits actuation with a transient thermal actuator. In the off state, this relay stands off more than 200 V. In the on state, it exhibits a minimum total resistance of(More)
This paper describes Robopsy, an economical, patient-mounted, telerobotic, needle guidance and insertion system, that enables faster, more accurate targeting during CT-guided biopsies and other percutaneous interventions. The current state of the art imaging technology facilitates precise location of sites within the body; however, there is no mechanical(More)
In poorly constrained extra-vascular environments such as hollow viscera, current catheter navigation techniques are restricted to simple paths and therefore limit a doctor's ability to position the catheter. This paper presents a new catheter positioning system that enables faster and more accurate catheter placement, with fewer scans. The proposed robotic(More)
This paper presents “Magnebots ”, a simple yet novel concept for overhead transportation. The system consists of vehicles with magnetic wheels that move on trackless ferromagnetic walls and ceilings, driven by on -board controllers and commanded by a central computer. Magnebots is designed to be a fundamentally simple technology that can fulfill many(More)
We present an in-depth study of CNT growth on commercially-available woven alumina fibers, and achieve uniform growth of dense aligned CNTs on commercially-available cloths up to 5 · 10 cm in area. By systematically varying the catalyst concentration, catalyst pre-treatment time, and sample position within the tube furnace, we isolate key factors governing(More)
The focus of this paper is on the design and evaluation of a robust drive mechanism intended to robotically steer a thermal ablation electrode or similar percutaneous instrument. We present the design of an improved screw-spline drive mechanism based on a profiled threaded shaft and nut that reduces the part count and simplifies manufacturing and assembly.(More)
We discuss growth of high-quality carbon nanotube (CNT) films on bare and microstructured silicon substrates by atmospheric pressure thermal chemical vapor deposition (CVD), from a Mo/Fe/Al2O3 catalyst film deposited by entirely electron beam evaporation. High-density films having a tangled morphology and a Raman G/D ratio of at least 20 are grown over a(More)